building blocks of the nervous system

2 types of NS

central nervous system - brain & spinal cord (CNS); Peripheral nervous system - cranial and spinal nerves & ganglia

what does the CNS comprise of?

brain and spinal cord

what does the PNS comprise of?

cranial & spinal nerves, and ganglia cells

what is the blood brain barrier ( BBB )?

a highly selective, semi-permeable membrane formed by specialized brain endothelial cells.

what is the function of the BBB

keeps pathogens & toxins out = lets nutrients & water & O2 in.

role and name of neurones?

nerve cells - functional unit of the NS and sends signals around the body.

role and name of glial cells?

acts as support cells - protecting and providing nutrients and immune functions to the neurones.

2 properties of neurones / nerve cells.

excitability - responding to a stimulus and converting it to a nerve impulse.; conductivity - ability to conduct an electrical impulse

structure of a neurone / nerve cell

Spire = dendrites at the tip top; Cockpit = cell body containing the nucleus; Body = Long Axon; Thrusters = Axon terminals at the end of the axons

what do the dendrites act as in the neurone / nerve cell?

recievers = they pick up the signal

What does the cell body do in the neurone / nerve cell?

Processor - computes the signal received from the dendrite

What does the axon do in the neurone / nerve cell?

distributes the signal received from the DENDRITE -> CELL BODY process to the axon terminals.

structure of the axon?

Long, Thin, Cylindrical projection.

how many axons are there in a neurone / nerve cell?

ONE

what is an axon specialised to do?

conduct action potentials.

what does the axon contain?

mitochondria and cytoskeletal proteins.

what is the order that the signal travels through in the nerve?

dendrites > cell body > axon > axon terminals

what are neuroglia?

cells that support and protect neurones.

are neuroglia able to divide & multiply?

Yes

what nervous system are microglia from?

the CNS

4 cell types that belong to CNS?

Astrocytes, microglia, ependymal cells, oligodendrocytes

what 2 cell types belong to the PNS

shwann cells and satellite cells

why are astrocytes called that?

named after their star-shape

what is the job of astrocytes?

make up the blood brain barrier (BBB), forms scar tissue post TBI etc. BASICALLY SUPPORTING CELL

NS that astrocytes belong to?

CNS

location & function of ependymal cells.

line ventricles of the brain, secreting cerebrospinal fluid & assisting in circulation of it.

what NS do ependymal cells belong to?

CNS

functions of ependymal cells

barrier function like astrocytes, selectively permeable allowing exchange of fluids.

function of oligodendrocytes?

provide structural support ( like scaffolding to neurones )

what do oligodendrocytes form for some CNS cells?

myelin sheath

what NS do oligodendrocytes belong to?

CNS

location and function of schwann cells?

PNS, covers the axon with myelin to make myelin sheath.

what is all other neural tissue called?

grey matter.

what are schwann cells involved in and act as?

involved in repair and regeneration, and act like insulation on a wire.

structure & function of satellite cells?

flattened cells arranged around the cell bodies of neurones - regulates the chemical environment & involved in repair.

what NS are satellite cells from?

PNS

what is a glioma?

a tumour of the glial cells.

what diseases are those caused by the loss of/ destruction of the myelin sheath?

MS, guillain barre syndrome.